1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method of the same, and particularly relates to a semiconductor device having a silicate film as an insulating film and a manufacturing method of the semiconductor device having the insulating film.
2. Related Background Art
A method of forming an insulating film with silicate is disclosed in Japanese Patent Application Laid-open No. 2000-49349 (hereinafter referred to as Patent Document 1). FIG. 1 and FIG. 2 are diagrams for explaining a process for forming the insulating film with silicate which is disclosed in Patent Document 1. As shown in FIG. 1, in Patent Document 1, there is disclosed a method in which after a silicate film is formed, the silicate film is subjected to deposition using a nitrogen source such as distant nitrogen plasma, NO, N2O, or NH3, and by this nitridation, nitrogen is supplied to silicate. Alternatively, as shown in FIG. 2, there is disclosed a method in which after a silicate film is formed, the silicate film is subjected to heat treatment and then nitriding treatment using NH3 or the like.
However, from a study of the present inventor, it turns out that when a necessary amount of nitrogen to prevent a layer from being isolated and crystallized is introduced into the silicate film, nitridation using NH3 is very effective. Moreover, it turns out that unlike when SiO2 is nitrided with NH3, when the silicate film is nitrided with NH3, nitrogen is introduced into the whole silicate film.
However, when nitridation using NH3 is adopted, the silicate film containing metal cannot be subjected to high-temperature and long-time heat treatment in terms of oxidation resistance and heat resistance even after nitrogen is introduced. Therefore, unlike when SiO2 is nitrided with NH3, hydrogen contained in the silicate film in the step of nitridation using NH3 cannot be fully eliminated in a subsequent step. Accordingly, as described also in Patent document 1, hydrogen remains in the film after nitridation, which causes a deterioration of reliability.